Intro to cells Flashcards
What are the 2 main cell types?
Prokaryotic: No nucleus (e.g., bacteria)
Eukaryotic: Nucleus & organelles (e.g., human cells)
What is the function of the plasma membrane?
Controls substance movement & responds to signals
What are the components of the plasma membrane?
Phospholipid bilayer, proteins, sugars, cholesterol
What is the function of the nucleus?
Stores DNA, controls cells activities, and directs protein synthesis
What is cytoplasm?
Gel-like fluid that fills the cell and contains organelles
What is the function of mitochondria?
Produces ATP (energy) through aerobic respiration
What is the role of ribosomes?
Protein synthesis
What is the function of the Golgi apparatus?
Modifies, packages, and transports proteins
What are lysosomes?
Organelles containing enzymes for waste breakdown
What is apoptosis?
Programmed cell death to remove old/damaged cells
What is the function of the cytoskeleton?
Provides cell shape, support, and movement
What are the 3 main cytoskeleton components?
microfilaments, microtubules, intermediate filaments
What is the function of the endoplasmic reticulum (ER)?
Rough ER: Protein synthesis (has ribosomes)
Smooth ER: Lipid synthesis & detoxification
What does DNA do?
Stores genetic instructions for protein synthesis
What is the role of RNA?
Helps in protein synthesis
What are the 2 stages of protein synthesis?
Transcription: (DNA–>RNA)
Translation: (RNA–>Protein)
What is the nucleolus?
A structure in the nucleus that makes ribosomes
What happens during mitosis?
A parent call divides into two identical daughter cells
What is necrosis?
unplanned cell death due to injury or lack of oxygen
How do lysosomes help the immune system?
They digest pathogens inside white blood cells
What is the function of transport vesicles?
Move proteins and molecules within the cell
What is the role of the sodium-potassium pump?
Maintains cell balance by moving Na+ out and K+ in
What is the role of peroxisomes?
Break down fatty acids and detoxify harmful substances
What is the interphase in the cell cycle?
The phase where the cell grows and prepares for division
What is the main function of epithelial cells?
Form protective barriers and aid in absorption & secretion
What is the main function of muscle cells?
Contraction for movement and force generation
what is the role of nerve cells (neurons)?
Transmit electrical signals for communication
What is the function of connective tissue cells?
Provide support, structure, and connect tissues
What is the extracellular matrix (ECM)?
A network of proteins & molecules that support cells
What is the role of stem cells?
unspecialised cells that can develop into different cell types
What is the basic unit of life?
The cell
What are the main functions of cells?
Growth, metabolism, response to stimuli, reproduction, and homeostasis
What is the process by which cells are replaced?
Cell division (Mitosis)
What is the hierarchy of biological organisation?
Cells~Tissues~Organs~Systems~Organism
What is homeostasis?
The body’s ability to maintain a stable internal environment
What are membrane proteins used for?
Transport, signaling, enzymatic activity, and structural support
What is cytosol?
The liquid portion of the cytoplasm where organelles are suspended
Why do cells age?
Due to accumulated damage and reduced ability to divide
What is difference between apoptosis and necrosis?
Apoptosis: Programmed cell death
Necrosis: Uncontrolled cell death due to damage
What is cytokinesis?
The division of the cytoplasm to form 2 separate cells
What is interphase?
The cell grows, duplicates DNA, and prepares for division
What are the main phases of the cell cycle?
Interphase and mitosis
What is a prokaryotic cell?
A cell without a nucleus or membrane-bound organelles (e.g., bacteria)
What is a eukaryotic cell?
A cell with a nucleus a membrane-bound organelles (e.g., human cells)
